Nine terpenoids were isolated from the petroleum ether extract of Carpesium abrotanoides L. by various column chromatography.Their structures were identified as 8-hydroxy-9,10-diisobutyryloxy-thymol (1),8,10-dihydroxy-9-isobutyryloxy-thymol (2),9-hydroxy-thymol (3),10-hydroxy-8,9-dioxy-isopropylidene-thymol (4),8-hydroxy-9,10-dioxy-isopropylidene-thymol (5),(3R,6R,7E)-3-hydroxy-4,7-megastigmadien-9-one (6),blumenol A (7),4-(3-oxobut-l-enylidene)-3,5,5-trimethylcyclohex-2-en-l-one (8),loliolide (9) by analysis of their NMR and MS data as well as by comparison with the literature.All the above compounds were isolated from C. abrotanoides for the first time,among which 3-8 were identified from this genus for the first time.All isolated compounds exhibited in vitro cytotoxicity against the HL60,A549,SMMC7721,MCF7 and SW480 cell line at the concertration of 40 μM.In addition,compound 2 displayed significant anti-tumor activity MCF-7,SW480,with the inhibitory rates are 72% and 81%,respectively.